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CYP19A1 variation in healthy children: associations with breast development and pubertal gynecomastia

Veronica L R Groendahl1,2, Stine A Holmboe1,2, Alexander S Busch1,2,3

  • 1Department of Growth and Reproduction, Copenhagen University Hospital - Rigshospitalet , Copenhagen, Denmark.

Endocrine Connections
|August 13, 2026
PubMed

Insights

Genetic variations in CYP19A1 may influence pubertal timing in girls. In boys, specific CYP19A1 genotypes are linked to pubertal gynecomastia and elevated estradiol levels.

Area of Science:

  • Endocrinology
  • Human Genetics
  • Pediatric Development

Background:

  • CYP19A1 gene encodes aromatase, crucial for converting androgens to estrogens and influencing breast development.
  • The role of common CYP19A1 genetic variations in healthy childhood pubertal development remains incompletely understood.

Purpose of the Study:

  • To investigate associations between CYP19A1 single nucleotide polymorphisms (SNPs) and pubertal development markers.
  • Examined relationships with estradiol (E2), testosterone (T), E2/T ratio, age at thelarche in girls, and gynecomastia in boys.

Main Methods:

  • Assessed 1023 healthy children (5.9-20.0 years) from the Copenhagen Puberty Study for pubertal status.
  • Measured serum sex steroid concentrations using LC-MS/MS and performed genotyping for CYP19A1 SNPs (rs727479, rs2899472, rs10046).

Main Results:

  • Girls with specific CYP19A1 genotypes (rs727479, rs2899472 AA) showed a tendency toward earlier puberty.
  • Boys with the rs727479 CC genotype had a higher prevalence of pubertal gynecomastia (73%).
  • Boys with gynecomastia exhibited elevated estradiol and testosterone levels compared to unaffected boys.

Conclusions:

  • CYP19A1 variants may play a role in determining pubertal timing in girls.
  • In boys, CYP19A1 genotype is associated with pubertal gynecomastia and linked to elevated estradiol concentrations.
Abstract

Keywords:
aromatasegenotypesgynecomastiapubertythelarche

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